His name is Slenderman, a faceless ghoul many parents had likely never heard of until this week.

Born in 2009, Slenderman was created as part of an online contest for supernatural enthusiasts. Often shown in a dark suit and sometimes with tentacles, his original story did not urge online readers to perform violent acts.

But like his tentacles, online enthusiasts have taken Slenderman in many different directions.

The two girls accused of stabbing their friend say they discovered the character on a website called creepypasta.wikia.com. They told police they wanted to kill their friend to show their devotion to Slenderman.

Dr. Bravada Garrett-Akinsanya is a child psychologist. Her office sees more than 2,000 kids a year.

“Part of it is that their plea for help pre-existed,” Garrett-Akinsanya said. “These kids have spent enormous time involved in the Internet, looking at this character, and so they kind of stop discerning fact from fiction.”

Dr. Garrett-Akinsanya believes one of the 12-year-old attackers likely has a mental health concern that was unaddressed, and the other may have simply been a follower. She says they got lost in a fantasy, and lost track of reality.

“It’s the overexposure plus the possible mental health possible condition that is creating the perfect condition for a perfect storm,” she said.

Slenderman videos have millions of views on Youtube, and there are even video games devoted to the character.

Dr. Garrett-Akinsanya believes the fact that the girls plotted to kill their friend for months shows displaced anger, and they used Slenderman as a sort of outlet.

She doesn’t believe parents are necessarily to blame. She says they are uneducated and really unprepared for all the Internet access kids have.

In this case, the girls basically became desensitized to violence. That’s why Dr. Garrett-Akinsanya wants parents to check Internet history on the IPad or computer.

“It’s a protective factor to have families, communities, who have eyes and hands on the child in their daily lives,” Dr. Garrett-Akinsanya said. “And somehow, these kids slipped through the cracks.”

She also says parents should look for warning signs like too much time spent alone or on the web.